From: Joel VanderWerf <vjoel@...>
Date: 2003-12-13T10:11:15+09:00
Subject: Re: create/read/write structs in ruby

Michael Hale wrote:
> I am creating an extension in ruby for a library with a sizeable amount 
> of sizeable structs.  I would like to be able to create c structs, set 
> their attributes, and read their attributes in ruby, for the purpose of 
> passing the struct I just setup to a native method that knows what to do 
> with it.
> 
> I am envisioning something like this:
> 
> require 'customtype.so'
> t = CustomType.new
> #writer
> t.property1 = 'some value'
> 
> #reader
> t.property1
> 
> Under the covers this would read/write the values on my c struct.
> The only way I can see to implement this would be to basically write a c 
> method for every attribute on the struct and then do some method missing 
> stuff on the ruby side.
> 
> Is there an easier/better way to read and write data from a struct in 
> ruby than what I have outlined?

Take a look at swig (www.swig.org). You can feed it your C/C++ source 
and it will generate the interface code you need to build a ruby 
extension. Some rather large C++ libraries have been wrapped in ruby 
this was (Fox --> FXRuby is a great example).